The specialist can reduce the eye pressure by 20% or more in several ways. First, by placing one or many stents in the drainage pathway inside the eye. Second, by applying a laser to the glands that produce the aqueous fluid inside the eye (endocycle photocoagulation or ECP). This can reduce the need for glaucoma drops after your cataract operation. The main risk in operating inside the eye is the risk of infection. It is helpful to treat glaucoma when you are already inside the eye removing the cataract.
Ms Crawley and her colleagues at The Western Eye Hospital at Imperial College Healthcare NHS Trust were one of the first and one of the biggest centres in the UK to offer ECP.
To not provide combined treatment for glaucoma with cataracts in one operation may be an opportunity missed. A combined treatment may improve the longer-term pressure control. It also may reduce the burden of drops for the patient who must take the treatment life-long.
The pressure inside the eye relies on the amount of internal aqueous fluid the eye produces. It also relies on the rate at which it is drained through the eye’s internal outflow pathway. This fluid and drainage are different to your tears which are external to the eye.
Endocyclophotocoagulation (ECP) means applying a laser to the ciliary body that produces the aqueous fluid under direct endoscopic vision. Endoscopy is the technique that passes a camera into spaces inside the human body. This allows us to identify issues, however small, with certainty. It is also used by doctors who examine the stomach and intestines.
Reducing the amount of aqueous produced is like turning down the tap- reducing the inflow part of the pathway.
The specialist carries the ECP out through the same incisions used for the cataract operation and adds 20 minutes to the operation. It can be performed under the same anaesthetic used for the cataract surgery.
A micro stent, often the iStent, is a snorkel device that the specialist inserts into the channels that drain the aqueous fluid out of the eye. This is placed into the drainage angle at the end of the cataract operation and adds 20 minutes to the end of the cataract procedure.
These micro-stents consist of titanium. They are currently the smallest implants used in the human body.
They are not detectable to the naked eye. Only an ophthalmologist can visualise them by looking into the drainage channels using a goniolens.
The post-operative recovery period is like the cataract surgery alone. Yet, this involves more than one procedure. It is usual to increase the frequency of the anti-inflammatory drops after the procedure from 4 x daily to 6 x daily. You may need the drops for 6 weeks rather than 4 weeks.